Telmisartan is a partial agonist of peroxisome proliferator-activated receptor gamma (PPARgamma), the working assumption is that telmisartan fosters the transition of monocytes to macrophages M2 form, and limit the recruitment of more monocytes in the kidneys and therefore proteinuria and renal fibrosis. To show this, it will be compared the ability of monocytes to differentiate ex vivo in M1 or M2 macrophages in diabetic nephropathy patients treated with losartan or telmisartan then it will characterize the role of PPARgamma in the monocyte / macrophage transition. Finally, it will be compared the urinary excretion of amino terminal propeptide of procollagen type 3 (PIIINP), considered a marker of renal fibrosis in patients receiving losartan or telmisartan.